Bonding means connecting system structures and enclosures together galvanically to maintain an equal electrical potential between the electrically conductive parts of a system. Bonding increases electrical safety and minimizes differential voltages.
Sometimes grounding is difficult or impossible to arrange so bonding is used instead. This applies, for example, to locations with extremely low soil conductivity (for example very dry locations) and Antarctica where the closest distance to soil is 2 km (1.24 mi) downwards, through the ice.